Det står ju tydligt på skylten att det även ska funka för ESTA. Denna från Dulles airport.
”eligible to use the CBP MPC app:
- U.S. citizens with a valid U.S. passport
- Canadian citizens with a valid
Canadian passport - Lawful Permanent Residents with a valid
LPR card - Visa Waiver Program travelers with a valid passport from a Visa Waiver country”
1) the airport contractor line controllers are sometimes wrong about who is and is not eligible to use MPC, so sometimes it works to just ignore them and simply show them the MPC app without showing them the passport; and
2) (the bigger issue) each CBP Port Director/Acting port director or assigned or on-duty airport-level CBP management can have their own ideas about what they think works for the CBP at a particular airport or at a particular time and decide to be more restrictive about whom they want to be able to use MPC at the airport(s)/terminal(s) under their personal supervision.